Steam shovel



H. J. BARNHART STEAM SHOVEL E() Sheets-Sheet l n Filed Nov. 5, 1921 @cito 25 E927.

H. J. BARNHART STEAM sHovEL 2 'sheets-sheet 2 F'iled Nov.

IIIIIIII MM. MN

F MABIN, ORIG, ASSGNOR TO THE OSGOOD CGMPANY, @I MARION, OHIU, A CBlEOMATIUN Ol OHIO. l

MY il. hARNHABT,

ST i i" im SHOWL llly invention relates to steam shovels or power excavating means of the type -genorally known as endless chain traction steam shovels and has to do with the provision of a a simple and positively operated means for steering the same. lt is customary to steer steam shovels of this type by disconnecting one of the traction units from its positive drive while maintaining the other traction lo unit in connection with its positive mechanism.

l have provided a novel form of steering mechanism which makes possible the ready disconnection of either traction unit under the control of a balanced power followed by the automatic locking of the disconnected traction unit. This balanced powerv is o such a nature and so applied that the parts will be positively moved in either direction to to edeot connection or disconnection of the traction unit and yet practically all jar normally resulting from movement of parts of this nature will be eliminated.

- My invention referably takes the form of a clutch mem er for each traction unit which is movable into and out of driving connection with the unit by means of a iluid motor and a spring, one acting to move the clutch in one direction and the other lacting 30 to move the clutch in the opposite direction but both acting against each other in some measure in the performance of their respective functions. rlhus, when the fluid pressure device moves the clutch, this movement t6 is resiliently opposed by the spring 'and when the spring moves the clutch this movement is resiliently opposed by a fluid cushion, due to the partially exhausted fluid in the Huid pressure device.

The preferred embodiment of my-invention is shown in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein Figure 1 is a front elevation of a steam 4% shovel truck together with the traction units therefor and showing my invention applied thereto. l

Figure 2 is a plan view of the structure shown in Figure 1. l

Figure 3 is a detail taken on line 3--3 of lEigure 1 and showing the automatically effective means for locking a disconnected traction unit against rotation.

ln the drawings, the truck of a steam shovel is shown at 1 as being mounted upon traction units 2 and 3. The positive driving f elements of these traction units take" the form of sprocket and chain constructions 4 and '5 which are only effective to positively drive the shafts 6 and 7 by means of clutch members 8 and 9 that are movable into and out of clutching relation with jaw teeth 10 and 11 upon the sprocket driven by the sprocket chains. Y

'lhe movable clutch members are provided with annular grooves. 12 and 13 within which fit collars 14 and 15 which are loosely connected to the bifurcated ends of yoke members 16 and 17 of levers 18 and 19. rlhese levers 18 and 19 are fulcrumed as at f 20 and 21.

Positively connected to the ends of the levers 18 and 19 are piston rods 22 and 23. The opposite ends of these piston rods fit loosely in sockets 24 and 25 in pistons 26 and 27. 'lhese pistons are mounted to reciprocate in open ended cylinders 28 and' 29.

The closed ends of these cylinders, which are the inner ends, are provlded with iiuid inlet pipes 30 and 31 which lead from a T 32 and which are respectively provided with hand-operated valves 33 and 34, Leading from the T is a iiexible piping 35 that is preferably extended upwardly into the steam shovel housin where it 1s supplied with steam from the oiler.

Connected to the. upper extremities of the levers 18 and 19 are rods 36 and 37 and theserods extend inwardly and pass through apertured brackets 38 and 39 upon the outer ends of the cylinders 28 and 29. The rods are surrounded by springs 40 and 41 inside of the brackets 38 and 39 and whose outer ends bear against these brackets while their .inner ends bear a ainst collars 42"'and 43 that may be held 1n position by adjustable l lock nuts 44 and 45.

Immediately above the inner ends of the shafts 6 and 7 and depending from the truck 1 are rigid dog members 46 and 47 and these dogmernbers are adapted to cooperate with cutaway portions 48 in the `anges 8 and 9 of the movable clutch members, the

function of theseparts being explained in the description of o eration.

The valves 33 an 34 are preferably rprovided with hand levers 49 and 50 so that these valves may be operated from the ound it desired. However, these hand litt detachable link members and 52 with levers 53 and 54 that are mounted upon the cab of the steam shovel.' of the shovel structure may be eected either by initially setting the levers upon the track or by operating these levers from the cab by means of the members 53 and 54.

ln the normal running of the steaml shovel along a straight road, both movable clutch members are in operative engagement with the jaw teeth and il with the result that the power is transmitted from the positively driven sprocket members t and 5 through the clutch members to the shafts 6 nl and 7. 'lhese shafts 6 and 7 then drive the traction units by means ci main sprocket members 55 and 56 whose teeth ht 1n apertures 57 and 58 in the 'tread members 59' and 60. ln this position, both et the springs Zl0 and di are distended and hold the movable clutch members in their driving position.

enever it is desired'to edectturning ol the steamshovel to one side or the other, one ci the valves 33 or 34 is operated to admit steam or other duid pressure to the cylinder on the side toward which the turn is to be made. dn had in 'Figure l where steam is beingintroduced into the cylinder 28 with the result that the piston 26 has been forced outwardly and has operated to move the lever i3 so as to move the movable clutch member out of driving position. Sincethe traction unit on this slde continues in contact with theground, thr 'shaft 6 continues to rotate with the dange member 8 in contact with the depending dog d6. However, as soon as one of the cutaway portions t8 of this Hangs 8 registers with this dogl d6, the movable clutch member-is moved further inward'so that the dog enters the cutaway portion and stops further rotation ci the movable clutch member with the result that rotation of the traction unit entirely, ceases. lt should be noted that this movement of. the clutch mem- ,ing has been l that .turning ber by the steam pressure is somewhat resisted by the spring d0 with the result that the movements of the parts is elected without jar. Then, when the' proper amount ol turning has been accomplished, the valve 33 is turnedto position to permit exhaust ol the .steam from the cylinder 28 through the en haust pipe 61, whereupon the spring d() moves the movable clutch member back into against the cushioning action of the steam which is thereby expelled from the cylinder 28. It will be apparent in the opposite direction isv edected in an identical manner by operation ot the valve 3d and that after sucient turnedected, the steam is caused to exhaust through exhaust pipe 62 in the manner explained Thus, the steering illustration ot this isl f motors tor moving lt will be apparent that l have provided an extremely simple and eective steering mechanism with practically all oi' its parts within the farea ot the trunk'irame and, therefore, out of the way yof the dipper which, being more or less unwieldy, is constantly striking various parts of the steam shovel structure with a consequent danger of breakage of these parts. lt will be obvious that l may use other forms of-duid motors or that some of the parts of this device may be transposed or altered without tion.

Having thus described my invention, what claim is:

l. @Power excavating shovel structure comprising traction units, means for driving said traction units, Huid motors including means for disconnecting said traction units trom said driving means, and springs for connecting said traction units' to said driving' means, said motors and said springs being balanced against each other when in action..

2. Power excavating shovel structure of the endless chain type comprising a revolvable cab structure, means for driving said traction units, means for connecting said tract-ion units to said driving means, means controllable from the cab tor disconnecting said traction units from said driving means, said last two means being balanced against each other when in action, and means controllable from the cab for locking vthe traction units against movement.

3. Power excavating shovel structure comprising traction units, power means ier driving said traction units, clutch members for connecting and disconnecting said traction units with said power means, duid said clutch members out of driving relation with said power means, and springs tor urging said clutch members into driving relation with said power means, said Huid motors and springs being balanced against each other when in action.

4l. vlilo'wer excavating shovel structure .comprising atraction unit, power means for driving said traction unit, a clutch member 4for connecting and disconnecting said traction unit with said power means, a locking device tor said clutch member, a Huid motor for moving said clutch member out of driving relation with said power means, and a resilient means for urging said disconnected clutch member into driving relation with said power means, said last two named means being balanced against, each other when in action.

5. Power excavating shovel structure comprising a traction unit, power meant' departing from the principles of my invenlid tor driving said traction unit, a clutch meer nume: l B

berf for connecting and disconnecting said Aa.- s ring secured to saidv lever for urging traction unit ywith said 'power means, a fiuid sai clutch member into driving relation l motor including a. cylinder and a piston with seidpower means.

operable within saidA cylinder .for moving In testimony whereof I hereby aix my U said clutch member out of driving relation signature.

with 'said power means, a lever secured to v said clutch member and said piston, and HARRY J.. BARNHART. 

